CLINICAL CORE The broad long-term objective of the UM BACPAC MRC Clinical Core will be to provide an enduring resource for the NIH BACPAC initiative. The data collected and cohorts established throughout the course of this project will remain a resource for a wide array of individuals and entities that conduct clinical pain research. The more immediate objective of the UM Clinical Core will be to provide the substrate for the successful completion of all four Specific Aims noted in the Overview for this application. The Interventional Response Phenotyping research project central to this effort will rely heavily on the patient population, existing registry, and research infrastructure of the Department of Anesthesiology?s Back and Pain Center at the University of Michigan and the experienced research team at the Chronic Pain and Fatigue Research Center (CPFRC). Both centers, working in concert, will make up the UM Clinical Core. The Michigan Medicine Back & Pain Center is a large tertiary care pain clinic that evaluates over 1500 new patients per year and conducts nearly three times as many return patient visits The Back & Pain Center has a pain patient registry (>8700) with rich pain phenotyping data, including numerous PROMIS measures, that are routinely collected from most of the new patients evaluated each year at the pain clinic. Further, there are nested cohort studies based on the data of registry patients, as well as randomized controlled trials that draw from them and are managed by the experienced study personnel. Similarly, the CPFRC has a long and rich history of successfully collecting the types of deep phenotyping data specified herein (e.g., neuroimaging, quantitative sensory testing [QST], inflammatory factors, ecological momentary assessment [EMA]) and has been a leader in the field of pain research for close to two decades. The UM Clinical Core will tap into our existing infrastructure and well- phenotyped patient population and address the following aims. First, the UM Clinical Core will provide the infrastructure and resources for the baseline assessment and both light and deep phenotyping data collection including the processing and analysis of neurobiological samples. Second, it will support the Interventional Response Phenotyping study through the recruitment, enrollment and retention of patient participants with chronic low back pain. Third, the UM Clinical Core will support the provision of the SMART design study interventions to be used in the Interventional Response Phenotyping study. Lastly, the clinical core will coordinate with the Informatics Core and Algorithm Development and Operations Management Center (DAC) for data management, statistical analysis and data sharing.